<template>
  <div>
    <h1>App</h1>
    info:{{ info }} <button @click="info.age++">+</button> <br>
    info.size.w:{{ info.size.w }} <button @click="info.size.w++">+</button> <br>



  </div>
</template>

<script setup>
import { reactive, ref, watch } from "vue";
const info = ref({
  name: 'jack',
  age: 20,
  size: {
    w: 100,
    h: 200
  }
});
watch(() => info.value.size.w, (newValue, oldValue) => {
  console.log(newValue, oldValue);
})






</script>